Perhaps you've never read the Bill of Rights:
Amendment I
Congress shall make no law... abridging the freedom of speech, or of the press...
You have three choices, sport:
1) prove that Congress did not pass the so-called 'campaign reform' law in question;
2) prove that political ads do not qualify as "freedom of speech, or of the press;" or
3) prove that a ban on such ads does not 'abridge' our free speech rights.
(This should be good... ;>)